How to distinguish white printing and dye printing?

1. Direct printing (Over print, Wet print)

Direct printing is a kind of printing directly on white fabric or on pre-dyed fabric. The latter is called overprinting (also called dyeing printing), of course, the color of the printed pattern is much darker than the dyed background. About 80% of printed fabrics on the market use direct printing. (Direct printing here generally refers to dye printing, which is used to distinguish it from the pigment printing below)

Question: How to distinguish white printing and dye printing?

If the front and back of the fabric are the same in depth (due to piece dyeing), and the printed pattern is much darker than the background, then this is an overprint fabric, otherwise it is a white printing.